VERITAS Storage Foundation 4.1 Oracle Administrator's Guide

VERITAS File System Prerelease 8 September 2005, 8:54am
38 VERITAS Storage Foundation for Oracle Administrator’s Guide
The QoSS option is built on the multi-volume support technology introduced in this release. Using
QoSS, you can map more than one device to a single file system. You can then configure policies
that automatically relocate files from one device to another, or relocate files by running file
relocation commands. Having multiple devices lets you determine where files are located, which
can improve performance for applications that access specific types of files and reduce
storage-related costs.
Support for Large File Systems and Large Files (Optional)
Support for large file systems is included with the Enterprise Edition.
In conjunction with VxVM, VxFS can support file systems up to two terabytes in size. For large
database configurations, this eliminates the need to use multiple file systems because of the size
limitations of the underlying physical devices.
Changes implemented starting with the VxFS Version 3 disk layout have greatly expanded file
system scalability, including support for large files.You can create or mount file systems with or
without large files by specifying either the largefiles or nolargefiles option in mkfs or
mount commands. See “Creating a VxFS File System” on page 67 for more information.
Multi-Volume File System Support
The multi-volume file system (MVS) feature allows several volumes to be represented by a single
logical object. All I/O to and from an underlying logical volume is directed by way of volume sets.
A volume set is a container for multiple different volumes. This feature can be used only in
conjunction with VERITAS Volume Manager.
Storage Checkpoint and Storage Rollback
The Storage Checkpoint and Storage Rollback features are included with the Enterprise Edition.
With the Standard Edition, they can be purchased as part of the VERITAS FlashSnap option.
VERITAS File System provides a Storage Checkpoint facility that allows you to create a persistent,
point-in-time image of all user files in a file system—the Storage Checkpoint remains even after
the file system is unmounted or the system is rebooted. Storage Checkpoints present a view of a file
system at a point in time, and subsequently identify and maintain copies of the original file system
blocks. Instead of using a disk-based mirroring method, Storage Checkpoints save disk space and
significantly reduce I/O overhead by using the free space pool available to a file system.
The time required to create a Storage Checkpoint is typically only a couple of seconds. After a
Storage Checkpoint is created, a consistent database backup image is made and the database can
then resume its normal operation.